1. Field of the Invention
The present invention relates to a single unit actuator, and more particularly, to an actuator capable of performing both rotational driving functions and linear driving functions via one unit.
2. Description of the Prior Art
In general, a motor is an actuator for converting an electromagnetic energy generated by an electromagnetic coil and magnets into machinery energy. Various kinds of motors including a pneumatic motor and an electric motor have been developed and are developing to meet the needs of the times. Particularly, the pneumatic motor is widely used in the field of large-size and heavy duty industrial machines, and the electric motor is widely used in situations where a compact and light weight motor is needed.
Generally, an actuator includes a rotor, installed at a hollow portion of a housing, for rotating an external device, and a driving unit, installed at a sidewall of the housing, for rotating the rotor. Various devices are used as the driving unit. The rotor is rotated by a piston, a gear or a turbine device in the pneumatic or hydraulic motor. In the electric motor, a rotational magnetic field is generated by applying an Alternating Current or Direct Current to a stator, and the rotor is rotated by mutual electromagnetic force acting between currents induced from the rotational magnetic field.
FIGS. 1A and 1B are views illustrating an actuator in the related art.
A conventional actuator includes, as shown in FIG. 1, an actuator 10 which is able to move in a straight line, and an actuator 20 which is able to rotate. The actuators 10 and 20 are selectively driven depending upon situations requiring rotation movement and linear movement.
In order to simultaneously perform the rotational movement and the linear movement, however, two actuators should be driven by a controller, and separate jigs are required to accurately arrange two actuators, which causes a spatial problem in smaller spaces. Furthermore, whenever separate jigs are used, it is difficult to obtain the position accuracy due to errors.